1. Field of the Invention
The present invention relates to a tube joint to which a fluid tube for introducing or discharging a fluid is connectable.
2. Description of the Related Art
A tube joint has been hitherto used in order to connect a fluid tube to a fluid pressure-operated apparatus such as a cylinder. Such a tube joint is provided with a body into which the tube joint is inserted. A fastening tab, which protrudes radially inwardly by a predetermined length, is provided for the body. The fluid tube is slightly pulled in a direction opposite to the direction of insertion after the fluid tube has been inserted. Accordingly, the forward end of the fastening tab is allowed to bite into the outer circumferential surface of the fluid tube to prevent the fluid tube from becoming disengaged from the body. The fastening tab is retained by an engaging member, which is installed on the body.
In the tube joint as described above, for example, the body sometimes is formed of a resin material in order to reduce its weight. In such a situation, when the fastening tab is allowed to bite into the fluid tube inserted into the tube joint, the body is pressed and becomes deformed in some cases, because the fastening tab is displaced radially outwardly. For this reason, a pair of ring members, each of which is composed of a metal material, may be installed on the outer circumferential surface of the body, so that the body, which is composed of the resin material, is prevented from becoming deformed radially outwardly (see, for example, Japanese Laid-Open Patent Publication No. 11-325362).